A scientific team in the Arctic discovers two mysterious cyborgs, similar to those described by
Zefram Cochrane. When they assimilate the scientists and move into space, Enterprise is called upon to find the cybernetic beings and stop them.

They break up, searching in different directions. Rooney picks her way quickly but carefully through debris and snow, until her scanner starts beeping. She stops, kneels and brushes away snow, uncovering something. She calls her comrades over to see what she has found.

It is the face of a frozen humanoid figure, unlike anything they have ever seen. Its skin is grave-pale, mottled with black. A grotesque cyberneticimplant is where its left eye should be.

They show Drake their findings. Moninger, after examining a bulky cyberneticprosthesis that one of the drones had on its right arm where the forearm should have been, has found that it had been integrated into the creature's circulatory and nervous system; it could have probably controlled the device as if it were its own flesh and blood. He has also examined the eyepiece of the first discovered drone, and has found that with it, the creature could have seen most of the electromagnetic spectrum. Rooney finds that their ship crashed about a hundred years prior. Drake instructs them to transmit the findings to Starfleet.

But as they speak, they hear a mechanical whirring, and see the tool at the end of the cybernetic prosthesis whirring and clicking. After a hundred years, frozen in ice and snow, it still works. A further examination of the prosthesis is in order.

Borg nanoprobes repair the cells of one of the drones

Moninger does the examination, looking at a bit of the tissue from the part of the prosthesis that was attached to the drone's bicep under a microscope. He shows Drake. Microscopic machines, some form of nanotechnology, are seen among the cells, repairing them. There are thousands of them in each creature. Not only are they regenerating the tissue, but they are repairing the mechanical parts. The prosthesis is fully functional.

As incredible as he finds this, however, Moninger also finds it disquieting. How far will this regenerative process go? These creatures do not look very friendly. What if they are fully revived and prove dangerous? And just what were they doing on Earth a hundred years ago? Did they come in peace or otherwise? He suggests that, just to be on the safe side, they freeze them again and examine them under more controlled conditions.

But Drake says no; re-freezing them might damage them. They will remain in the laboratory and the regeneration will be allowed to continue. He goes outside to where Rooney is further investigating the ship's debris.

Her report to him is that, from the fact that every piece of outer hull debris has precisely the same curvature, the ship appears to have been a perfect sphere, about six hundred meters in diameter.

Meanwhile, another researcher brings a thermos of a hot beverage for Moninger in the lab. Before he leaves, he looks at the two drones and voices concern; will Moninger be OK? Moninger assures him that he will, showing him a rifle he has for protection.

Alone again, Moninger pours a cup of the beverage. Then he hears a mechanical clicking noise from one of the drones. Alarmed, he checks the monitor that displays the drone's neural activity. Nothing.

Outside, Drake and Rooney have found something else: a Borgtranswarp coil. But though they can guess as to its function, i.e. faster-than-light space travel, the technology is, of course, way beyond them.

A drone revives

Inside the lab, Moninger still watches the monitor. Then, suddenly, a spike appears. Then more spikes, then full signals; neural activity has begun in the drone's brain. The drone awakens with a gasping breath. Moninger grabs a scanner and begins scanning it, as it opens its organic eye. Its mouth closes and its face lapses into a cold stare, as it beholds him.

Outside, Drake and Rooney hear his scream.

The beginning of Moninger's assimilation

They rush back to the lab. They find one drone on the slab where they left it. The other is gone. And they find Moninger behind some tossed-over shelving, gasping painfully. The left side of his face is streaked with black lines that spread out, as the nanoprobes that the revived drone injected him with multiply rapidly and begin to assimilate him. Drake tells Rooney to get a medical kit. She turns to do so, and turns right into the revived drone, its organic eye staring at her coldly, the red laser of its eyepiece on her face.

The remains of the research team's laboratory

Three days later, at Starfleet Headquarters, CommanderWilliams rushes into the office of senior Starfleet official AdmiralMaxwell Forrest. He informs the Admiral about the prolonged loss of contact with the research team. Forrest orders him to ready a shuttlepod. He and an armed team go to the site. All they find is snowed-in, abandoned shells of structures; no sign of the research team or the debris from the crashed ship.

Out in space, aboard Enterprise, CaptainJonathan Archer speaks to his senior staff in the conference room. Admiral Forrest has informed him of what has happened and has sent him the data the scientists gathered, believing the creatures abducted the research team. The transport the team used was detected leaving Earth at warp 3.9.

This shocks the chief engineer, CommanderTucker; these transports cannot exceed warp 1.4. Archer surmises that the "aliens" improved the ship's systems using technology from the wreck of their own ship. The transport's projected course puts it within six light years of Enterprise's current position. Forrest has ordered that they intercept it and rescue the research team.

SubcommanderT'Pol surmises that isolating the transport's warp signature should not be difficult. Archer decides that the search should start at specific coordinates, which he inputs onto the table's display. He orders a tactical alert and orders Ensign Travis Mayweather to lay in the necessary course.

Reed and Phlox discuss weapons the drones may possess

As the ship heads for the area, LieutenantMalcolm Reed, the armory officer, speaks to DoctorPhlox, the chief medical officer, about the "aliens" possible weapons. He and Phlox look at the research team's biometric data on the creatures, but find no evidence of weapons. This worries Reed; the team was well armed; how did these two "aliens" manage to overpower them without weapons?

Enterprise continues toward the coordinates. Captain Archer is in his ready room, reading something on his computer terminal. Then T'Pol calls him to the bridge; they are receiving an automated distress call from a Tarkalean freighter. He goes out onto the bridge, where Ensign Hoshi Sato at the communications station tells him what the message says: the freighter is under attack. He orders Mayweather to alter course toward it.

The assimilated transport attacks a Tarkalean freighter

The freighter is seen, banged up and dead in space. The transport, heavily modified and with the same color and external texture as a Borg vessel, now looks very menacing, far from the ordinary-looking vessel that was seen earlier. It is seen cutting into the freighter with a cutting beam.

Enterprise arrives. Archer orders a hail to the transport, warning to cease and desist immediately or be fired on. The transport responds with a volley of proton bursts at Enterprise. T'Pol scans nine Human life signs on the transport, but the readings are erratic. Reed believes he can disable its weapons; Archer orders it done. Enterprise fires on the transport, which breaks off its attack and takes off at warp. Archer orders a shuttlepod deployed to the freighter to bring the survivors aboard.

The assimilated male Tarkalean

The survivors, two in all, a man and a woman, are seen lying unconscious in sickbay. Their faces and hands are marred with emerged Borg implants. Archer and T'Pol are present. Phlox informs them that the two should live, but then shows them what is happening to them: the nanoprobes (he uses the actual correct term) in their bodies are transforming them into "some sort of cybernetic hybrid." T'Pol surmises this as the reason for the erratic Human life sign readings; the research team is likely being similarly transformed.

Archer asks if the nanoprobes can be removed. Phlox says no; they are multiplying extremely fast; he could never remove them all. T'Pol advises that the two should be secured in the decontamination chamber. But Phlox makes the same terrible mistake the research team's leader made; he says that he cannot treat them properly there, and he does not believe them to be a danger to the crew. However Archer is not so sure. He will have Reed post a guard.

Later, in his ready room, T'Pol comes to tell him she has contacted Tarkalea and informed them of their rescue of their people. Archer shows her what he was reading before. It is a speech that was given 89 years prior by Human history's inventor of warp drive, Dr. Zefram Cochrane. In it he had spoken about the events surrounding his first warp flight. He had spoken of a group of cybernetic creatures from the future who had intended to "enslave the Human race". They had tried to prevent the flight, but were stopped by a group of Humans, also from the future. (Star Trek: First Contact)

T'Pol reminds Archer of Cochrane's over-active imagination and the fact that he was frequently drunk. Archer acknowledges this, saying that nobody took the story seriously and Cochrane recanted the whole thing years later. But there are similarities between the story and these current events that cannot be ignored. And if the story was indeed true, then these creatures may be heading back to where they came from, so that another attempt can be made.

In sickbay, the two Tarkaleans begin to stir. Phlox goes to the male, who wakes up very agitated on seeing him. He demands to know who Phlox is and his location, and is horrified to see the implants in his hands. Phlox tries to calm him down, then picks up a hypospray with a sedative to administer it to him, as he suddenly convulses and screams with pain.

Phlox is injected with nanoprobes

But then, as Phlox comes close, the Borg implants take full control of their victims. On the other bed, the woman rises behind the guard Reed posted in the room. The man grips Phlox's arms with incredible strength, and the woman throws the guard all the way across the room. The man forms a fist and brings it to Phlox's neck. Assimilation tubules dart out, injecting Phlox with nanoprobes. He throws Phlox over the bed. Phlox collapses in a heap on the other side, unconscious.

The two head for a ladder leading to a maintenance shaft exiting the room. They are now Borg drones; instead of running to the ladder, they march quickly with implacable purpose, in the way that drones do when on their way to perform a function as directed by the Borg Collective. All they are missing are the prosthetics and the exo-plating.

Phlox regains consciousness and picks himself up off the floor, assisted by Captain Archer. Before regaining consciousness, however, he hears voices in his mind. The words "assimilation" and "unimatrix" are heard distinctly. Reed is present with Archer, along with security officers, all well-armed. Phlox reports what happened; the aliens attacked and injected him with nanoprobes. Scans by the security officers reveal their path of exit from the room up the ladder. Archer orders Reed to seal off the shaft, post guards at every access point, find and subdue them. Phlox warns Reed about their greatly enhanced strength and to avoid being touched by them. Meanwhile the two drones move through maintenance shafts, never rushing, but moving quickly nonetheless. They come to a set of wall panels, remove the covers and inspect the circuitry.

Archer and Tucker discuss what they are up against

In engineering, Commander Tucker shows Captain Archer scans of the modified transport. It has been greatly enhanced, with more powerful engines, armor plating, weapons, and other modifications Tucker cannot even guess the functions of. Archer notices that the aft plating has not yet been enhanced; a couple of torpedoes should break through and knock out a nearby EPS manifold, disabling the ship.

Then T'Pol calls from the bridge; she has detected the transport, less than two light years away, moving at warp 4.8; a significant development; its top speed has doubled in less than twelve hours. Archer orders Ensign Mayweather to alter course to intercept it.

Meanwhile, in the maintenance tubes, Reed and his security officers move carefully, looking for the drones, using scanners to track them down. They find displays that, instead of showing what they should, are filled with strange green script on black backgrounds. Borg script.

Reed and the security team fail to stop the drone

They come upon the drone that used to be the Tarkalean woman altering more panel circuitry. It is seen plunging its assimilation tubules into the circuitry, which instantly becomes modified to Borg standards, taking on the familiar black and green color. Reed sternly and repeatedly orders it to stop, but it continues after a cursory glance at them. They fire their weapons at it. The shots merely make it lose balance a bit. And then subsequent shots hit nothing but Borg personal shield. They crank the weapons up to maximum power, fire again. Again, nothing but shield.

However, their attacks cause the drone to register them as a threat. It turns and advances on them. Remembering Phlox's warning, they quickly withdraw, only to run into the drone that used to be the male Tarkalean. It overpowers one of them and tries to inject him with nanoprobes. But Reed whacks the drone in the head with the butt of the officer's fallen rifle, temporarily stunning it. He calls the bridge and reports the location of the drones to Captain Archer, and what they appeared to have been modifying systems. Archer asks T'Pol what is in that area. Her answer: warp plasma regulators, essential for the warp engines to function.

The drones are ejected into space

Suddenly Mayweather reports the destabilization of the ship's warp field; they are falling out of warp. The drones have disrupted the regulators. Without warp, Enterprise has no chance of ever catching the transport. Archer recalls that there is an outer hatch in that area. He orders Reed and his officers to clear the area and seal it and orders Ensign Mayweather to bring Enterprise down from warp. When this is done, he orders T'Pol to open the hatch. She does so. The drones are instantly blown out into space. At Archer's order, T'Pol then closes the hatch and re-pressurizes the area.

He is dismayed at having to resort to this. But T'Pol tells him he had no choice. Archer orders course for the transport resumed, and orders Reed to work with Tucker to find out exactly what the drones were doing to the systems.

In sickbay, Ensign Sato brings food for Phlox and his small menagerie of little alien animals. He accepts her offer to feed the animals, but he will not eat himself, for fear of accelerating his metabolism and causing the nanoprobes in his system to spread even faster. He now has a sickly white and black-mottled patch over the tubule wounds. She desires to stay and keep him company once she finishes but he insists that, for her own safety, she leave immediately when done. "I underestimated these nanoprobes once; I do not intend to make the same mistake twice," he tells her.

Meanwhile, Tucker and Reed examine the modified circuitry but they cannot determine what has been done to it.

Captain Archer goes to the officers' mess. T'Pol is there. She advises him that perhaps it is better not to try to rescue the Humans, saying that it is logical to assume that all aboard the transport has either been transformed or are transforming and that bringing any of them aboard may be extremely dangerous. The transport should be destroyed, she adds. But Archer is not ready to do this. Then Phlox calls him, asking him to come to sickbay.

His condition has worsened. His hands tremble, the Borg patch on his neck has spread over the entire right side of his face, a second patch has formed on his forehead and a third is forming on his right hand. He tells Archer that his Denobulan immune system seems to be baffling the nanoprobes, but they are persistent and will adapt and keep multiplying. Eventually, he will be transformed. However he has found a possible treatment. Their processors appear to be susceptible to omicron radiation. Exposure to this may destroy them and cure him, but the level has to be very high, lest even one nanoprobe survive. Such a high level would be very painful.

Should it fail, he has one surefire cure: death. He gives Archer a hypo containing a toxin that will almost instantly end his synaptic functions, and asks him to use it if the treatment fails. Archer is shocked, but Phlox is resolute: he will not allow himself to be turned into one of these "cybernetic creatures".

Reed (right) tests phase pistol modifications

In the armory, Reed and one of his security officers test modifications of phase pistols and rifles to try to get them to penetrate the Borg personal shields. A particular setting works. They begin modifying as many weapons as they can. They work quickly; Enterprise will catch the transport in less than an hour.

Sure enough, less than one hour later, they come upon it. Its defenses have been further enhanced since their last meeting. It accelerates almost to the limit of Enterprise's speed, warp 5. Archer orders speed increased to match. The ship begins to shudder with the effort, but they close the distance. Archer orders Reed to target the EPS manifold that he and Tucker agreed on.

The transport attacks Enterprise

The transport drops out of warp. Ensign Sato reports an incoming transmission; it is an activation sequence. On Archer's order, she tries to stop it, but cannot. The Borg-modified circuits suddenly become active. Main power and other systems, including weapons, begin to fail. Archer angrily realizes the truth: the drones sabotaged the circuits, modifying the appropriate systems so that this signal would cause them to fail.

Then Sato reports a hail coming in. Archer orders it answered. He angrily begins to identify himself and Enterprise. But he is cut off. Cut off by words spoken in a cold, soulless, multi-track resonant intonation: "You will be assimilated. Resistance is futile.'

They are the Borg.

Enterprise is seen dead in space, while the transport is seen closing on her like a hungry wolf on a helpless lamb.

The transport hammers Enterprise with weapons fire, wearing down her defensive polarized hull plating. Commander Tucker feverishly works trying to undo the drones' sabotage so that they can at least regain use of weapons. But it will take several minutes. Captain Archer gets an idea. He asks Reed if the transporter is still working. It is. He orders Reed to come with him, telling T'Pol to be ready to beam them off the transport.

Phlox undergoes his painful cure

Meanwhile, in sickbay, Phlox's condition has worsened considerably. Both sides of his face now look Borg, as well as both hands. He again hears voices in his mind. His movements are hunched and painful. His voice is tremulous. But he determinedly sets up the omicron treatment, telling the guard to activate it once he is in the chamber. He gets in. The guard activates it. Lights strobe over Phlox. He grimaces and grits his teeth in agony.

Captain Archer and Lt. Reed, armed with Reed's modified phase pistols, beam onto the transport. Its interior has been completely assimilated and modified, including the presence of Borg alcoves. They carefully pass by regenerating drones. Archer scans for any possible victims to be rescued.

The transport continues to hammer Enterprise.

The drone that used to be Rooney

Suddenly, two drones round a corner and march toward them. They fire, unaware that they will be ignored as long as they do nothing threatening, and the drones drop. The two men check them. They are two of the scientists from the Arctic. On scanning them, Archer realizes that he labors in vain to rescue them, or anyone else on the transport. These two are no longer Human. The one he scans used to be Rooney.

Then more drones round the corner, having registered them as a threat due to their previous action, the drones advance on them. They withdraw, making their way to the EPS conduit they tried to destroy before.

Meanwhile, things get much worse on Enterprise as six drones board her. T'Pol, as first officer, dispatches security to try to stop them, but the officers experience the same result as Reed and his team did against the drone that used to be the Tarkalean woman: their shots kill a few, then hit nothing but force fields on the remaining drones when they adapt. The drones advance relentlessly, pushing the officers ever backward. Meanwhile, Commander Tucker manages to isolate one of the power relays and begins to reroute power to the engines and weapons.

On the transport, Archer and Reed continue toward the conduit, killing drones that try to stop them. Each one Archer scans confirms unrecoverability. Reed's modifications of the pistols work for now; they kill several drones. But it will not be long before the Borg adapt. They find the conduit and Reed quickly places bombs on it while Archer fends off advancing drones.

At the same time, Enterprise's polarized hull plating finally fails and the transport begins to use its cutting beam on her hull.

But Archer and Reed succeed in mining the conduit. Just as the drones finally adapt to their weapons, he has T'Pol beam him and Reed back. As soon as they materialize on the transporter platform, he has Reed detonate the bombs. The desired effect is achieved: the transport's power is disrupted. The cutting beam stops. At the same time, Trip manages to disable the Borg circuitry on Enterprise, restoring power to the Enterprise's systems. Returning to the bridge, Archer is asked about the research team by T'Pol. He tells her: there is no longer anyone aboard they can help.

The transport is destroyed

But then the drones that boarded Enterprise beam off. Reed reports with alarm that the transport's systems are being restored; it is charging weapons. Archer is now versed enough in what they are dealing with to know exactly what to do; he orders full weapons directed at the transport's warp core. Enterprise fires all her weapons at the transport, which explodes as she quickly departs. The transport destroyed, he grimly orders Sato to contact Admiral Forrest before going off to his ready room.

Later, with Enterprise having resumed her original course, he and T'Pol go to sickbay to see Phlox. He has fully recovered; the omicron treatment was successful.

T'Pol and Archer discuss the dispatched Borg subspace signal

But Phlox has ominous news; he tells them about the "strange experience" he had while he was infected; the voices in his mind, as if he were part of a collective intelligence. T'Pol suggests he hallucinated it. But he does not think so; he got the distinct impression the "aliens" were trying to send a subspace message: a numerical sequence he heard over and over again. He gives them a PADD with the numbers.

Later, T'Pol goes to see Archer in his ready room. He has had the computer analyze the numbers. The results have him even grimmer than before. They are spatial coordinates; Earth's spatial coordinates. The drones sent a message detailing Earth's location. T'Pol asks him where the message was sent to. His answer: deep inside the Delta Quadrant. T'Pol tells him that there is no immediate worry as a subspace message would take at least two hundred years to get there, providing it even makes it at all.

This does not comfort Archer, however. He surmises that the invasion has merely been postponed...until the 24th century.

"You seem a little jumpy."
"Cybernetic corpses, digging through frozen remains in the middle of the night. Why would I be jumpy?"

- Drake startles Rooney after they find Borg in the Arctic

"Buried in the ice for a century."
"Hard to believe anything could survive."
"Handsome devil."

- Tucker and Archer viewing images of the Borg taken in the Arctic

"What sort of people would replace perfectly good body parts with cybernetic implants?"
"You, of all people, should be open-minded about technology."
"Well, I don't have a problem with it... so long as it stays outside of my skin."

- Reed and Phlox

"I don't believe they're a danger to the crew."

- Phlox on the assimilated Tarkaleans

"Use extreme caution, Lieutenant, their physical strength has been enhanced. It is critical that you do not let them touch you."

- Phlox, having been injected with nanoprobes

"They set us up!"

- Archer, angrily realizing the formerly-Tarkalean drones have sabotaged Enterprise and left them defenseless against the assimilated transport

"They've adapted!"

- Archer, when the drones aboard the assimilated transport adapt to his and Reed's phase pistol fire, later a common phrase to use during Borg encounters

"..., you will be assimilated. Resistance is futile."

- The Borg

"I doubt there's any immediate danger. It would take at least 200 years for a subspace message to reach the Delta Quadrant, assuming it's received at all."
"Sounds to me like we've only postponed the invasion, until what... the 24th century?"

However, when confronted with the script some production (fan) staffers were initially less than enamored, or as Production Illustrator John Eaves has put it, he being called upon to design Arctic One and its subsequent "borgification", "During Season II of Enterprise we got wind of a future script #49 called Regeneration. everyone in the art dept.. started to read the little teaser and we all gasped in Horror at about the same time, THE BORG!!! NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!. We all were not feeling to happy about this new TNG alien showing up in an episode of Enterprise before Kirk...well this will throw all lines of trek history out the window. A few days later the first script arrived and reluctantly we all went to our desks and read away...Hey this is OK I thought It does work and it ties into Trek history as defined in First Contact. As you recall The Borg sphere went back in time to destroy the Phoenix warp ship thus changing earths history and killing the threat of Humanity in the future. The Sphere gets fired upon by the Enterprise-E and the evil plot is eliminated...Now we are working on Enterprise and this new story picks up on the debris from the sphere being discovered in Antarctica. like "the Thing" once thawed out the Borg go back to doing what they do best! Assimilation! My job on this one was to create an Arctic exploration vessel that makes the discovery and later becomes Borgified. The fist sketch is high profile vessel that I thought when Borged could form a cube. This idea was passed on and the second sketch got the approval. The ship is lightly based on a stylized snow mobile. Once Borged it goes thru a variety of changes and this second sketch try’s to convey on of the stages of coverage. Pierre over at Eden modeled this one(...)" [1]

In the original premise, the assimilated Earth shuttle was to have transformed into a partial Borg sphere by assimilating more ships over the course of the episode, analogous to a snowball growing as it rolls down hill. However, this idea was dropped from the script, although in the final confrontation between the Enterprise and the shuttle, the segment of the ship containing the transwarp drive had been reconfigured into a small cube shape which dominated the hindquarters of the ship.

In the first draft of the script, the Arctic research station was to have been "scooped" off the planet, leaving only a crater behind (as seen in TNG: "The Best of Both Worlds"). It was decided by the producers that only a Borg cube would have this capability, so the debris was simply removed from the ice field, presumably carried away by the drones.

When the assimilated transport attacks the Tarkalean freighter, and later Enterprise, it is seen cutting a circular chunk into their hulls. This was an allusion to TNG's "Q Who", when the Borg take a cylindrical cross-section of the USS Enterprise-D. The writers had initially hoped to show the cylinder being tractored away from the Tarkalean freighter, but the effect was deemed too expensive.

The scene where Reed tests phase pistol efficiency was added at the last minute, as David Livingston's quick form of directing left several minutes to be filled.

Reed's line about shooting the Borg drones with holographic bullets was an in-joke by the episode writers. In the holodeck scene in Star Trek: First Contact, drones could indeed be killed by holographic bullets, assuming the holodeck safety protocols were turned off.

The invasion that Archer predicts does indeed happen in the 24th century, in 2366, 213 years after the events in "Regeneration". (TNG: "The Best of Both Worlds")

The episode has a much darker theme than other instalments of Enterprise, reinforced by the music score composed by Brian Tyler. This is the second episode of season two to feature music scored by Tyler. The first was "Canamar".

There was some controversy among fans over the fact that the Borg drones omitted their standard greeting ("We are the Borg") when they hailed Enterprise, conveniently keeping Starfleet in the dark about the identity of the cybernetic species. In their podcast commentary, the writers' justified this by pointing out that the Borg in TNG: "Q Who" never said "We are the Borg" when they encountered the USS Enterprise-D, nor did they use that catchphrase when they confronted Picard's ship again in TNG: "The Best of Both Worlds". One theory concerning this is that the Borg only identify themselves as such if a Borg Queen is present, but is only supposition.

The episode introduces a potential predestination paradox into the overall Borg story arc. At the end of the episode, it is revealed that the assimilated Earth freighter dispatched a subspace message to the Delta Quadrant. T'Pol theorized it would take at least two hundred years for the message to reach the Delta Quadrant, implying that this may be how the Borg Collective originally learned of Humanity's existence (it is worth noting there is no evidence the signal was actually received). If the message was received, it may explain why, in the 24th century, the Borg specifically wanted Captain Picard to speak for them and why they sent at least one vessel to the vicinity of Federation space, destroying several Romulan and Federation outposts in 2364. (TNG: "The Neutral Zone") A series of incidents with the Federation followed over the next several years, culminating in the Battle of Sector 001, wherein a Borg sphere travelled to the 21st century in an effort to assimilate Humanity in the past. (Star Trek: First Contact) The sphere was destroyed, and several drones from the vessel were frozen in an Arctic glacier in 2063, which were uncovered by the Arctic scientists 90 years later in "Regeneration", starting the causality loop all over again. It is also worth noting that if the signal which was sent by the Earth freighter was not received by the Borg, then the Borg's first contact with the Federation and Humans would have been by way of assimilation of the USS Raven in 2356. If, however, the signal was received then the information in the transmission would have been 200 years out of date by the time the Borg received it.

The events of this episode form the basis of the story for the 2006 non-canon game Star Trek: Legacy. A Vulcan scientist named T'Uerell is assigned to study the Borg debris and after learning their true nature, injects herself with Borg nanoprobes. Armed with knowledge of future events, she spends the next two centuries building her forces and waiting for the opportunity to seize control of the Borg Collective in order to use them to bring a state of total logic to the Alpha Quadrant.

On the broadcast of this episode on Channel 4 in the U.K. several scenes were edited including Phlox being injected by nanoprobes and his attempt at curing himself with radiation.

This episode contains the only mention of the Delta Quadrant in the entire run of Star Trek: Enterprise.